Conventionally, cells have been cultured by repeatedly performing the following operation. A culture medium and cells are put in a Petri dish, the Petri dish is housed inside an incubator in which environment such as temperature and atmospheric gas is controlled with a top lid closed to thereby culture the cells, the Petri dish is taken out of the incubator at every predetermined period and transferred to an operation space in which dispensation and separation are performed, the culture medium is replaced in the operation space, and the Petri dish is again returned to the incubator. When a culture medium replacement operation is manually performed, it is necessary not only to pay careful attention to prevent various germs and contamination from being mixed therein during the operation, but also to perform the culture medium replacement in every two or three days. Further, the replacement time may be midnight. Therefore, researchers and operators have been forced to bear heavy labor and burden. In view of the above, in recent years, there has been provided an automatic cell culture apparatus capable of automatically replacing a culture medium.
Patent Document 1 discloses a cell culture apparatus in which a culture cassette with a Petri dish housed and held therein is freely detachably placed inside an incubator and a gas pipe for introducing and discharging gas is detachably connected to the culture cassette having a sealed structure to thereby perform cell culture while controlling the temperature, gas, and the like. The incubator is provided with an opening/closing door which can be automatically opened and closed. The opening/closing door is opened, and the culture cassette is taken out and transferred to an operation room using a robot hand. Thereafter, a lid body of the culture cassette is opened, and the Petri dish is taken out using another robot hand and set at a predetermined position in the operation room. After performing treatment such as a fractionating/dispensing operation for replacing the culture medium and an inspection operation, the Petri dish set in the operation room is housed in the culture cassette in the reverse procedure of the above procedure, and the culture cassette is then returned to the incubator. In the fractionating/dispensing operation in the operation room, a top lid of the Petri dish is detached using a robot hand, and the main body of the Petri dish is inclined inside the operation room to collect the old culture medium in one side. Liquid of the collected old culture medium is sucked out using a suction tool, a new culture medium is then filled in the Petri dish, and the top lid is then attached thereto.
Patent Document 2 discloses an automatic cell culture apparatus that is provided with an operation unit for performing a culture operation necessary for culturing cells of subjects, incubator units for culturing the cells, storage units for storing reagents necessary for culture and culture tools, a steam supply unit for performing autoclave sterilization, and an inlet-outlet unit for taking in and out reagents and culture tools. The incubator unite, the storage units, and the inlet-outlet unit communicate with the operation unit, and have sealing doors leading to the operation unit. By selecting and opening/closing the sealing doors, sterilizing steam from the seam supply unit is supplied to the operation unit, and any of the incubator units, the storage units, and the inlet-outlet unit communicating with the operation unit.
The operation unit is provided with an operation robot, a centrifugal separator, and a culture operation unit which is necessary for culturing cells. The culture operation unit includes a turntable, a pipetting device, and a centrifugal tube handling device. The culture operation necessary for culturing cells includes a culture medium replacement operation and a subculture operation. As also described in Patent Document 3, a general-purpose multijoint industrial robot is used as the operation robot that carries out an actual culture operation on behalf of human resources. A multijoint industrial robot can perform substantially the same operation as manual operation by controlling the robot by a computer. Further, a multijoint industrial robot can also perform different operations by rewriting a control program and therefore has versatility. However, because a multijoint industrial robot is extremely expensive, an automatic cell culture apparatus is also a large-scale and expensive system and therefore cannot be easily utilized.